Update async Dispose and methods references (#22407)

* Update async Dispose and methods references

- `Dispose` can be changed to  `DisposeAsync`
- The methods in the following code snippet are not available, it causes duplicate references

```
        /// <summary>
        /// <see cref="HelperResult.WriteTo(TextWriter)"/> is invoked
        /// </summary>
        /// <param name="result">The <see cref="HelperResult"/> to invoke</param>
        protected void Write(HelperResult result)
        {
            Write(result);
        }

```

* Update BaseView.cs

Author: hueifeng

src/Shared/RazorViews/BaseView.cs

@@ -69,7 +69,7 @@ public async Task ExecuteAsync(Stream stream)
             Output = new StreamWriter(buffer, UTF8NoBOM, 4096, leaveOpen: true);
             await ExecuteAsync();
             await Output.FlushAsync();
-            Output.Dispose();
+            await Output.DisposeAsync();
             buffer.Seek(0, SeekOrigin.Begin);
             await buffer.CopyToAsync(stream);
         }
@@ -87,7 +87,7 @@ public async Task ExecuteAsync(HttpContext context)
             Output = new StreamWriter(buffer, UTF8NoBOM, 4096, leaveOpen: true);
             await ExecuteAsync();
             await Output.FlushAsync();
-            Output.Dispose();
+            await Output.DisposeAsync();
             buffer.Seek(0, SeekOrigin.Begin);
             await buffer.CopyToAsync(Response.Body);
         }
@@ -244,13 +244,13 @@ protected void WriteAttribute(
             WriteLiteral(trailer);
         }
 
-        /// <summary>
+       /// <summary>
         /// <see cref="HelperResult.WriteTo(TextWriter)"/> is invoked
         /// </summary>
         /// <param name="result">The <see cref="HelperResult"/> to invoke</param>
         protected void Write(HelperResult result)
         {
-            Write(result);
+            result.WriteTo(Output);
         }
 
         /// <summary>